package com.yhsimon.facade;

/**
 * @author： YHSimon
 * @date： 2021-09-03 17:04
 */
public class Screen {
    private Screen() {

    }

    private final static Screen instance= new Screen();

    public static Screen getInstance(){
        return instance;
    }

    public void up(){
        System.out.println("screen up");
    }

    public void down(){
        System.out.println("screen down");
    }


}
